Randomized study with five groups to receive one of the following vaccination regimens after a birth dose of hepatitis B vaccine: One of the 3 lots of GSK Biologicals' Hib-MenAC mixed with GSK Biologicals' Tritanrix™-HBV (3 different groups) GSK Biologicals' Tritanrix™-HBV/Hiberix™ GSK Biologicals' Tritanrix™-HBV/Hiberix™ +Meningitec™